Hydraulic brake



(No Model.) 7 Sheets-Sheet 1. I'. L. CLARK.

. HYDRAULIG BRAKE. No. 574,663. n Patented Jan. 5, 1897.

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(No Model.) 7 Sheets-Sheet 3. F L CLARK HYDRAULIC BRAKE.

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(No Model.) 7 Sheets-Sheet 4.

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HYDRAULIC BRAKE.

Patented Jan. 5, 1897.

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No. 574,6,6fs` A1 6L1enrtedJan. 5,1897.

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.- F. L. CLARK. HYDRAULIC BRAKE.

No. 574,663. Patented Jan. 5, '1897. l

WITNESSES:

(No Model.) 'y 7 sheets-sheen?. F; L. CLARK.

`l HYDRAULIG'BRAKB.

WITNESSES:

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sus co.. Puurautno.. wAsuwcrrau n c UNjiTnnf STATES PATENT FFICE.

FRANCIS L. CLARK, OF STEWART STATION, PENNSYLVANIA.

-HYDRAU LIC BRAKE.

SPECIFICATION forming part of lIfetters Patent No. 574,663, dated January 5, 1897.

Application filed Jannaryl, 1896. Serial No. 575,548. (No modela 13e it known that I, FRANCIS L. CLARK, a citizen of the United States, residing at Stewart Station, in the county of Vestmoreland and State of Pennsylvania, have invented or discovered a certain new and useful Improvement in Hydraulic Brakes, of which improvement the following is a specification.

The object of my invention is to provide a brake apparatus designed more particularly for electric or cable railroad ears, in which, by mechanism readily and inexpensively applicable in connection with any of the ordinary constructions of ear-framing and running-gear, braking power adequate to the maximum requirements of service, either normal or emergency, may be derived, as from time'to time required, without the continuousA operation of a pump or compressor, from an axle of the car and be transmitted lo the wheels through an incompressible-fluid medium, as water or other liquid containing material of such character as will prevent frecz-.

infr.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings, Figure 1 is a side view in elevation of a car-frame, running-gear, and brake apparatus, illustrating an application of my invention Fig. 2, a plan or top view of the same; Fig. 3, a view, partly in elevation and partly in section, illustrating the general construction of a brake apparatus embodying my invention as applied to operate the brakes of two cars; Fig. 4l, a side view in elevation and on an enlarged scale of a portion of a brake apparatus embodying my invention; Fig. 5, a similar view, but partly in section, of an adjoining portion; Fig. 6, a similar view, partly in section, of the remaining portion; Fig. 7, a view in elevation of the lever mechanism of Fig. (3 as seen from the left; Fig. 8, a vertical central section through the excess-pressure or safety valve; Fin'. 9, a partial transverse section through the pumpdriving ring connected to a car-Wheel; Fig. 10, an end view of the pump-valve casing; Fig. 11, a vertical longitudinal central section through the same; Fig. 12, a vertical central section through the controlling-valve of the pipe system; Fig. 13, a longitudinal central section through apair of hose-couplings; Fig.

1l, a View, partly in elevation and partly in section at the line as 000i Fig. 15, of the pump and its supportingframe; Fig. l5, a vertical section through the same at the line y y of Fig. 14; Fig. 16, a longitudinal central section through the brake-cylinder and its pistons; and Fig. 1'7, a similar section through the brake-cylinder with the pistons shown in 6o elevation and in the positions occupied when the maximum amount of wear of the brakingsurfaces and slaekness in the conn ection have been allowed.

My invent-ion is in this instance illustrated 6 5 as applied to a four-wheeled electric ear, to which, as will be seen, it is readily applicable by reason of not involving the necessity for any change in or'alteration of the construction or location of the electric motor or other 7ov members of the running-gear. It is not, however, limited in adaptability to -this or any other specific construction ol car, and may without essential variation of structural features or operative principle be utilized in street-railroad or other service for braking either a single car or a train of cars of any of the known forms.

In the practice of my invention as herein exemplified the brake apparatus is connected So to and, except as to its operating-lever and controlling-valve mechanism, supported below the frame 1 of a car, which is carried upon four wheels 2, the axles of which are journaled in suitable bearings in side f 1ames 3. 85

The essential elements of the apparatus, which, with their accessories, will be hereiny after fully and in detail described, are apump 4, which is suspended from the car-frame in such manner that it may be moved into and 9o vout of position for actuation by the rotation of an axle of the car; a system of piping 5 5a, &c., through which a suitable liquid, as water containing some antifreezing material, may be circulated by the pump; a brake-cylinder 6, one or more of whichy may be employed, two being shown in this instance, each having a piston which is by preference specially constructed' to provide for automatieally taking up slackness and wear and 10o which is connected to one or more brake-shoes 7 a valve device 8 or 8, which controls the circulation' of liquid through the pipe system 5 5, dre.; and an operating-lever mechanism for moving the pump into and out of position for actuation and for effecting the opening and closure of the controlling-valve device 8 or S.

The controlling-valve and operating-lever are shown as duplicated in order to enable the brake apparatus to be operated from either end of the car; but it will be obvious that when these members at one end ot' the car are operated the corresponding members at the opposite end remain inactive.

The pump 4, the specific construction of which is not an essential of my present invention, is in this instance shown as of the single-acting reciprocating-piston type and as provided with two cylinders and pistons. The pump-cylinders -l -i (see Figs. l-.t and 15) are secured removably to a sleeve or tubular extension D, which projects centrally from one side of a supporting-frame 10, near the ends of which are fitted pins 11, on each of which is journaled a friction-roller 12. The frame 10 is suspended from the car-frame by links or hangers 13, the upper ends of which are journaled on a pin 1l, litting in a casting 15, secured to the car-frame, and the lower ends are journaled on the pin 1l which is nearest to the upper end of the frame 10. The frame 10 is also coupled by a pin 1G, located in or near the horizontal axial plane of the tubular extension 9, to the middle or body portion of a bell-crank lever 17, the upper arm of which is pivoted by a pin 18 to the casting 15 and which has its lower arm coupled by a pin 1U to a lever system, to be presently described, by which the frame l0 and the members connected thereto are moved toward and from a driving ring or pulley 20, which is formed in two halves or sections, connected by bolts 21 and secured by tapbolts? tothe inside of one ofthe car-wheels 2.

The driving-ring 2O may, if preferred, be made integral with the wheel 2 in the manufacture thereof.

A pump-shaft 23, which is litted to rotate in the tubular extension J of the frame l0, carries upon a squared portion of its length located between the sides of the frame a driving-roller 24, the periphery of which projects beyond the frame, so that when the latter is moved sufficiently close to the dri\f'ing-rin e,` 20, as shown in Fig. 5, the driving-roller iZ-t and one of the friction-rolls l2 are brought into frictional contact with the driving-ring, rotation being thereby imparted to the driving-roller 2l and pump-shaft 23.

An eccentric 25 is formed or iixed upon the pump-shaft at the portion thereof which is lof cated between the pump-cylinders l, and two eccentric-straps 2G 26 are fitted around it,cach strap being provided with a short arm or rod 27, which is coupled by a pin 2S to a piston 29, tting the adjacent pump-cylinder l. Each ot the eccentric-straps 26 is cut away for the major portion of its width, so as, through said portion, to only surround about one-half of the periphery of the eccentric. The remaining minor portion of the width of each eccentric-strap completely encircles the eccentric, and the complete and cut-away portiens are located at alternately opposite ends of the respective straps, as seen in Fig. 15. By this construction a large bearing-surface for the eccentric-strapsis provided during the forcing-strokes of the pistons and the bearing of the pistons on the eccentric is made more nearly central than would otherwise be the case. The en d ot the tubular projection t) farthest from the frame 10 is closed by a screwcap SO, which serves as an end bearing :for the pump-shaft 23.

The outer ends of the pump-cylinders 4 are connected with a system of pipes 5 5, the., through which a suitable non-freezing liquid, as, for example, water containing some antifreezing ingredient or mixture, lis caused to circulate when the pump is actuated by the rotation of the pump-shaft The pipe-sections 5,which connect directly with the pumpcylinders, lead therefrom inte chambers 32 in a valve-casing 31, (shown in section in Fig. 1 1,) supported below the car-frame, said chambers having openings in their upper and lower sides controlled, respectively, by upwardlyopening puppet-valves and 34; and leading, respectively, to an upper outlet-chamber 35 and to a lower inlet-chamber 3o. A pipe 5"l leads from the outlet-chamber to a controlling-valve device S, located adjacent to one end of the car in position to be conveniently operated by the motorman or other person directing the movement of the car, and a pipe 5b leads from the valve device S to a similar valve device S, located in corresponding position near the opposite end of the car. A pipe 5C leads from the valve device S to the inlet-chamber 36 of the valve-casing 3l. The controlling-valve device 8 or S may be either a simple plug-cock, as shown in Fig. 3, or an upwardly-opening puppet-valve 37, workingin acasing S,to which the pipes 5 and 5b are connected, and having an outwardlyprojecting stem 3S for closing it by a handactuated lever, as shown in Fig. 12.

The pipe 5, which leads from the outletchamber 35 of the valve-casing 31, is connected by a branch pipe 5d with what may be termed a train-pipe 5, having` a flexible hose-section 23S) and coupling-section 40 at each of its ends for connection to a correspending pipe on another car, and provided with cocks 4l l-l, by which it may be closed at either or both of its ends, as required. Branch pipes 5" 5f lead from the train-pipe 5C to each of the brake-cylinders (i of the car, there being two brake-cylinders in the instance shown. A by-pass pipe 5tr leads from the pipe 5C to the train-pipe 5, and an excesspressure or safety valve 12, which is held normally seated by a spring 13 or by a weight, is seated on a passage in a valve-casing il, interposed between two sections of the bypass pipe A vertical pipe 5" leads from the pipe 5c into a chamber 45, having a suit- IOO IIO

able glass gage on its side through which the height of the liquid may be observed, in order that any undue amount of leakage thereof may be compensated by a renewed supply.

With the above construction a circulation of liquid is maintained, when the pump is operated and both the controlling-valve devices S and S are open, through the pipes 5,

5f, 5b, and c in the direction indicated by the arrows in Figs. 2 and 3, and liquid is also supplied to the train-pipe and brake-cylinders, the liquid in the latter, as well as that in the several pipes of the system, not then being under pressure. When, however, either of the controlling-valve devices S or 8a is closed, the circulation of liquid in the pipe system is stopped and the continued action of the pump imposes a pressure upon the liquid by which the pistons of the brake-cylinders are forced outwardly therein and the connected brake-shoes applied to the wheels of the car. If the pressure should become unduly high, the excess-pressure valve 42 is thereby unseated and the circulation is reinstated to such degree and for such period as will relieve the excess.

The couplings 40, by which the train-pipe 5e is connected to a train-pipe upon a trailer or other car coupled to that on which the brake apparatus is mounted, as indicated in Fig. 3, may be of any suitable known construction, and are preferably of the type provided with valves which close automatically when the coupling-sections are disconnected. A form suitable for the purpose is shown in Fig. 13, each of the coupling-sections being provided with a valve 46, adapted to close its fluid-passage, said valve being held unseated when the sections are coupled by a doublearmed lever 47,'pivoted to the coupling-section and having one of its arms fitting in a slot in the stem of the valve 47 and the other adapted to engage a cam or inclined groove 4S in the section. When the lever 47 is released from the cam-groove, which is done in the act of uncoupling the sections, the valve 46 is seated by a spring 49 bearing on its back. The valve is correspondingly unseated by the engagement of the lever and cam-groove in coupling the sections.

Each of the brake-cylinders 6 is fitted with a properly-packed main piston 5l, which is preferably, as shown in Figs. 16 and 17, adapted to impart applied pressure to its piston-rod 52 in such manner as to automatically and continuously take up wear and slackness or lost motion of the rubbing-surfaces in the operation of the apparatus. In the construction illustrated, which is desirably adapted to this end, the main piston 5l, the traverse of which need only be comparatively short, is fitted in a counterbore at the end of the brake-cylinder to which liquid is admitted, which end is closed by a head or cover 52, to which the liquid-supply pipe 5 is connected. The outward traverse of the main piston 5l in effecting an application of the brakes is 'limited by a shoulder 53 atv the inner endof the counterbore, against which the adjacent follower-plate 54 abuts at the end of the stroke of the piston in that direction. On the backward movement of the piston. the opposite follower-plate 55 abuts against the cylinderhead 52. A supplemental piston 56, to which the piston -rod 57 is secured, is fitted with suitable packing in the smaller bore of the cylinder beyond the shoulder 53 and is recessed or bored out centrally to receive a central stem 58, which projects from the inner side of-the main piston 5l. As originally fitted up, the end of the stem 5S abuts against the bottom of the recess in the supplemental piston 56, which is consequently moved directly by and with the main piston 5l throughout the traverse made by the latter in effecting an application of the brakes. Ahelical spring 59, which bears against the head of the brakecylinder through which the piston-rod passes, returns both the main and the supplemental pistons to their normal positions upon the release of pressure from the main piston.

A passage 60 extends through the main piston 5l and is controlled by an inwardly-opening check-valve 61,-which is held normally seated by a spring 62 and is guided by a central stem 63, fitting a corresponding bore in the stem 58 of the main piston. A by-pass or conduit 64, controlled by a cock 65, which is normally closed, leads from the larger bore of the brake-cylinder Vpast the main piston 5l to the outer end thereof.

In operation the liquid from the supplypipe 5CL raises the check-valve 6l and fills the space between the main and supplemental pistons, after wl1icl1,thepressurein said space being equalized with that in the supply-pipe, the spring 62 seats the check-valve 6l. As the surfaces of contact of the brake-shoes and the wheels become worn and lost motion or slackness is developed in the connections between the piston-rod and brake shoe or shoes the diminished resistance to the movement of the supplemental piston 56 which results therefrom permits the pressure of the liquid supplied through the pipe 5f to raise the check-valve 6l, thereby admitting a sufficient quantity of liquid to the space between the main and supplemental pistons to move the supplemental piston out of contact with the central stem of the main piston and outwardly for a sufficient distance to take up such wear or slackness, whereupon, the pressure being equalized on opposite sides of the mainpiston, the check-valve is closed by its spring, and the main piston thereafter acts upon the supplemental piston in effecting the outward movement of the latter through the intermediation of the incompressible body of liquid interposed between the pistons. The admission of liquid is similarly effected coincidently and correspondingly with increase of wear or slackness or both, the supplemental piston being progressively moved away from the main piston until IOS IIO

it has advanced so far in the cylinder as to prevent it from making as great a stroke as that of the main piston. The cock 65 of the by-pass 0i is then opened and the liquidreleased from the space between the pistons until they are again brought into contact, as in Fig. 16, when the cock 65 is closed, and proper renewal or adjustment of the frictional surfaces and connections having been made, so as to take up the wear and slackness and bring the parts to normal condition, the further operation of the pistons is effected as above described. The intermediate'mechanism through which the force applied to the piston 5l is transmitted to the brake shoe or shoes is not, in and of itself, an essential of my invention, and any suitable and preferred system of brake connections heretofore employed for the purpose may be adopted in the discret-ion of the constructor. rlhe specific system illustrated, in which the piston of each brake-cylinder actuates the brakeshoes of two wheels, is, however, desirably applicable in point of simplicity and facility of application and is of the following construction.

Referring more particularly to Fig. 4, iu which this portion of the apparatus is most clearly shown, the brake-cylinder 6 is supported below the frame 1 of the car and between two of its axles and is in this instance bolted to a casting 6G, secured to the frame. A stout fulcrum rod or bar (57 is fitted freely by a rounded or spherical-faced end in a recess in the head 52 of the brake-cylinder, and its opposite end is coupled by a pin U8 to the lower end of a link or hanger 69, the upper end of which is coupled by a pin to a block or bearing on the ear-frame. The piston-rod 57 is coupled by a pin 7l to the lower end of a similar link 72, the upper end of which is coupled by a pin 73 to a block or bearing on the car-frame. The piston-rod is also coupled by the pin 71 to a double-armed brake-lever 74, the lower end of which is coupled by a pin to the brake-shoe 7 of the adjacent carwheel 2. The upper end of the brake-lever 74 is coupled by a rod 7G to the upper end of a corresponding brake-lever 77, the lower end of which is coupled by a pin 78 to the brakeshoe 7 of the car-wheel on the corresponding end of the next axle, that is, the axle toward which the fulcrum rod or bar G7 extends. The brake-lever 771s also coupled by the pin GS tothe fulerum rod or bar (57 and the link (Si).

Vhen the piston-rod 57 is forced outwardly to apply the brakes, its first action is to move the brake-lever 7l bodily in the same direction until the adjacent brake-shoe 7 is brought into and held in contact with the adjacent wheel 2. The further outward traverse of the piston-rod 57 then moves the brake-lever 74 upon the pin 75 as a fulcrum, the upper end of said brake-lever moving to the right in Fig. aand, through the connecting-rod 76, moving the brake-lever 77 in the same direction upon the pin 7 8 as a fulcrum, and thereby applying the connected brake-shoe 7 to the tread of the wheel ad jacent-t0 which it is suspended. Upon the release of pressure in the brake-cylinder, effected by opening whichever of the controlling-valve devices 8 or S as has been closed for making an application ot the brakes, the spring 5U, surrounding the piston-rod, (shown in Figs. 1G and 17,) returns the parts to the release positions indicated in Fig. et.

As shown in Fig. 3, the operating-lever mechanism for moving the pump into and out of position for actuation is shown as adapted to be worked by the foot of the operator and the controlling-valve device as operated by hand, while in Figs. 1, 2, 5, (5, and 7 both the pump-moving mechanism and the controlling-valve device are operated by a hand-lever. Referring iirst to Fig. 3, the supportingframe l0 of the pump 4 is coupled, by a pin 15, located in its middle portion and on the side farthest from the driving-ring 20, to the lower end of a double-armed lever 17, which is pivoted between its ends, by a pin 18, to a suitable support on the ear-frame. The upper end ot' the lever 17l is coupled by a link S0 to the arm 8l on a rock-shaft S2, which is journaled in a suitable bearing on the car-frame and which is provided with an oppositely-extending arm Si and an arm 83, substantially at right angles to the arms S1 and Si. The arm S3 is coupled to the lower end of a rod S5, having a treadle 86 on its upper end and litted to move vertically in a guide fixed to the ear-frame l. A spring 87, bearing against a shoulder on the rod 85, holds the latter normally in its highest position, in which, through the connections above described, the supporting-frame l0 of the pump is suspended in such relation to the adjaeentcar-wheel that the rollers l2 l2 and 24- are out of Contact with the driving-ring 20 and the pump is consequently inoperative.

By pressure upon the treadle the spring S7 is compressed and the downward movement of the rod S5, through its connections with the supporting-frame lO, moves the latter into such position that one or the other of the rollers 12 (according to the direction of movement oi' the car) andthe roller 21 will be brought into frictioual contact with the drivin g-ring 20, thereby7 effecting the actuation of the pump during such period as said contact is maintained by the continued depression of the rod 85. Upon the relief of pressure from the treadle 8U the parts are returned to normal position by the spring S7.

The arm 8l of the rock-shaft 82 is coupled by a rod SG to an arm Sln on a corresponding rock-shaft similarly connected with a spring treadle-rod SGan near the opposite end of the ear. The connecting-pins of the rod 86 and rock-shaft arm 84 and oi' the rock-shaft arm 83 and treadle-rod 85 iit in longitudinal slots, so as to prevent movement of the treadle-rod and connections at one end of the car when the treadle at the other end is operated.

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The plug-cocks of the controlling-valve devices 8 8a at opposite ends of the car are respectively operat ed, as required, by handles 92 9, fixed upon their stems.

In the operating-lever mechanism illustrated in Figs. 1, 2, 5, 6, and 7 the horizontal armr of the bell-crank lever 17, to which, as before stated, the pump-supporting frame 10 is coupled by a pin 16, is pivoted by a pin 19 to the lower end of a rod 79, the upper end of which is coupled to an arm 8l on a rock-shaft S2, journaled in a bracket or depending arm 93, fixed to the car-frame. The rock-shaft 82 carries substantially at right angles to the arm S1 two oppositely-extending arms 83 84, the upper of which is connected by a rod 85 with the lower end of a lever 88, which is pivoted by a pin S9 to the lower end of a vertical standard 90, fixed upon the car-frame near one end of the car, said standard also supporting on a lateral projection near its top the controlling-valve device S. The lower arm 84 of the rock-shaft 82 is connected by a rod S6 with a lever 8S, located at the opposite end of the car from the lever 88 and provided with accessions similar to those of the latter, as presently to be described, in order to admit of the manipulation of the pump starting and stopping mechanism and of a controllingvalve device from either end of the car, as required. The connections of the rock-shaft arm 83 and the rod S5 and of the rock-shaft arm 84 and the rod 86 are made by pins fitting in longitudinal slots, so as to prevent movement of the lever 88 or S8LL at one end of the car when the corresponding lever at the opposite end is operated.

A lever 94 is journaled on the pivot-pin S9 of the lever S8 and extends above the top of the standard 90. A hand-lever 95 is pivoted by a pin 96 to the top of the lever 94 and is provided with two arms 97 98, which project from it in opposite directions from the axis of its pivot. A dog or latch 99 is pivoted by a pin 100 to the standard 90 in such position that its free end may slide over the top of the lever 88, which is curved toa radius struck from the. center of the pivot-pin 89' of said lever and is provided with two lateral projections 91 91, one of which abuts against the standard 90 and the other against one side of the lever 94 when the levers stand in the positions occupied during the operation of the' pump, as shown in Fig. 6. An angular recess 101 is formed in the freev end of the dog or latch 99, which is coupled to the lower end of a rod 102, the upper end of which is hooked or bent over to engage a pin 103 on the arm 98 of the hand-lever 95, which arm is downwardly prolonged beyond said lpin to form a toe 106, which, when the hand-lever 95 is swung to the left on its pivot 96, abuts aga-inst the adjacent side of the lever 94.

A helical spring 104 surrounds the rod 102 and bears at one end against a projection on the standard 90 and at the other against a nut 105, which engages a thread on the rod, and

may be adjusted longitudinally thereon to vary the tension of the spring 104, as may from time to time be required. The lower face of the arm 97 stands immediately above and slightly clear of the top-of the stem 38 of the controlling-'valve 37 in the periods of release ofthe brakes, the valve 37 being then free to be unseated'by the iiuid circulated through the pipe system during the operation of the pump.

When it is desired to make an application of the brakes, the pump is first putin operation by bringing the levers 95, 94, and 88 and their connections into the positions shown in Figs. 5, 6, and 7, which is done by simply raising the dog or latch 99 from engagement with the lever 88, which lever is then moved by the spring 80 into the position shown in Fig. 6 and the pump is moved into the position shown in Fig. 5. The hand-lever 95 is then moved to the right, thereby depressing the stem 3S of the controlling-valve 37 and closing said valve, which is held seated by the pressure of the Operator on the hand-lever 95. The pressure generated in the pipe system by the actuation of the pump thereupon immediately applies the brakes, the application of braking force being continued, so long as the valve 37 is held closed, until the car is stopped. To release the brakes, the operator releases his pressure on the handlever 95, which is thereupon returned by the spring 104 to the position shown in Fig. G, when the valve 37 is unseated by the pressure of the liquid beneath it, the free circulation of liquid in the pipe system is reinstated, and, the pressure on the brake-cylinder pistons being thereby released, the springs 59, acting in the opposite direction thereon, withdraw the brake-shoes from contact with the wheels.

To stop the operation of the pump, the handlever 95 is moved to the left, which iirst brings the toe 106 to a bearing against the side of the lever 94 and thereafter moves the lever 94 coincidently with the lever 95. The lever 94, by its bearing on one of the projections 91 of the lever S8, throws the upper end of said lever to the left and the lower end to the right, and through the rod VS5 and its connections raises the lower arm of the bell-crank lever 17 and moves the supporting-frame 10 of the pump away from the wheel, thereby removing the rollers from contact with the drivin g-ring and stopping the operation of the pump. Vhen the upper end of the lever 88 has been moved to the left of the dog or latch 99, the spring 104 throws the angular recess 101 ofthe dog or latch into engagement with the righthand side of the upper end of the lever SS, holding said lever in the inclined position shown at the right of Fig. 1 and holding the supporting-frame 10 away from the wheel.- The levers 94 and 95 may then be returned to the position shown in Fig. 6, leaving the lever S8 locked in position by the dog or latch. To renew the operation of the' pump, it is only necessary to raise the dog or latch 99 out of en- IOO IOS

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gagcment with the lever 8S, when the spring SO, Fig. 5, returns the lever SS, the supportingframe 10, and the intermediate connections to the positions shown in Figs. 5 and (i.

A leading and characteristic feature of advantage of my improvement is the fact that the momentum of the car is utilized as the braking force, which is consequent-ly provided without the expenditure of any power Whatever over and above that required for the propulsion of the car. A further advantage is presented in the material reduction of Wear of the pump and its actuating mechanism as compared with prior constructions, in which a pump which is operated continuously during the movement of the car is employed. No perceptible time is required for the generation or accumulation of braking power, as the brake apparatus is ready for operation as soon as the pump is started, and the exertion of braking power to the full or to a partial extent, as may be required, is effected instantaneously by the total or partial closure of the controlling-valve device, as the case may be.

It will further be seen by reference t0 Fig. 2, in Which the motor mechanism of an electric car is indicated by dotted lines, that my improvement is readily applicable to cars of this class, and that no modification of or interference with the motor mechanism ordinarily employed is involved in such application.

I claim as my invention and desire to secure by Letters Patentl. In a brake apparatus, the combination, substantially as set forth, of a pump-supporting frame, a suspension-link connecting said frame to the frame of a railroad-car adjacent to a wheel thereof, a driving ring or pulley formed or fixed on said wheel, a pump-cylinder connected to the supporting-frame, a piston working in said cylinder, a pump-shaft journaled in the supporting-frame, connections for reciprocating the piston from sa-id shaft, a driving-roller iiXed upon the pumpshaft and a friction-roller journaled in the supporting-frame, each in position to bear against the wheel-driving ring, mechanism for moving the supporting-frame into and out of position for the driving and friction rollers to make Contact With the wheel-driving ring, a pipe system through which liquid may be circulated by the pump, and a brake-applying mechanism actuated by pressureimparted l r substantially as set forth, of abrake-cylinder to liquid in the pipe system by the pump.

2. In a brake apparatus7 the combination, substantially as set forth, of a pump adapted to be intermittently operated from a car-axle, a pipe system through which liquid may be circulated by the pump, a brake-applying mechanism actuated by pressure imparted to liquid in the pipe system by the pump, mechanism for transferring the pump into and out of position for actuation, lever mechanism located adjacent to each end of the car, for actuating the pump-transferring mechanism, and connections between said lever mechanisms for enabling either to be' operated independently of the other.

3. In a brake apparatus, the combination, substantially as set forth, of a pump adapted to be operated from a car-axle, a pipe leading from said pump to a casing provided with a receiving and a delivery valve, a pipe leading from the delivery-valve chamber to acontrolling-valve, a pipe leading from the controlling-valve to the receiving-valve chamber, a pipe leading from one of said pipes to a brakecylinder, a piston fitting said brake-cylinder, a brakeshoe connected to said piston, and mechanism operative independentlyof variation in the pressure of the liquid in the system for instituting and discontinuing the operation of the pump and actuating the controlling-valve.

4. In a brake apparatus, the combination, substantially as set forth, of a pump adapted to be operated from a car-axle, a pipe leading from said pump to a casing provided with a receiving and delivery valve, a pipe leading from the delivery-valve chamber to a controlling-valve, a pipe leading from the controlling-valve to the receiving-valve chamber, a by-pass pipe establishing a circulation from the receiving to the delivery valve chamber, independently of the controlling-valve, an cX- cess-pressure or safety valve governing said by-pass pipe, a pipe leading from one of said pipes to a brake-cylinder, a piston fitting said brake-cylinder, a brake shoe connected to said piston, and mechanism operative independently of variation in the pressure of the liquid in the system for instituting and discontinuing the operation of the pump and actuating the controlling-valve.

5. In a brake apparatus, the combination, substantially as set forth, of a pump adapted to be operated from a car-axle, a pipe leading from said pump to a casing provided with a receiving and a delivery valve, a pipe leading from the delivery-valve chamber to a controlling-valve, a pipe leading from the controlling-Valve to the receiving-valve chamber, a train-pipe connected with one of said pipes and provided with an end coupling and cock, a pipe leading from one of the before-recited pipes to a brake-cylinder, a piston tting said brake-cylinder, and a brake-shoe connected to said pist-on.

C. In a brake apparatus, the combination,

connected to a car-frame between wheels of two axles of a car, a fluid-supply pipe leadin into said cylinder, a piston fitting said cylinder, a piston-rod fixed to said piston, a doublearmed brake-lever coupled to said piston-rod and to a suspension-link, a brake-shoe pivoted to one end of said brake-lever, a fulcrum rod or bar fitting freely in the head of the cylinder and extending therefrom in opposite direction to the piston-rod, a double-armed brake-lever coupled to the fulcrum rod or bar and to a suspension-link, a brake-shoe pivoted to one IOO IIO

end of said brake-lever, and a rod or link coupled to the opposite 'end of said brake-lever, and to the corresponding end of the brakelever which is directly connected to the piston-rod.

7. In a brake apparatus, the combination, substantially as set fortln'of a brake-cylinder, a fluid-supply pipe leading therein to, a piston fitted in a counterbore at the supply end of said cylinder, a piston fitted to traverse in a smaller bore eXtendin g from the counterloore toward the opposite end of the cylinder, a piston-rod fixed to the smaller piston, a retracting-spring bearing on said smaller piston, a tubular projection on thelarger piston which enters a recess in the smaller piston, and initially bears thereon, and a spring-seated valve controlling the passage of fluid through the larger piston to the space between the two pistons.

S. In a brake apparatus, the combination, substantially as set forth, of a brake-cylinder, a fluid-supply pipe leading thereinto, a piston fitted in a counterbore at the supply end of said cylinder, a piston iitted to traverse in a smaller bore extending from the counterbore toward the opposite end of the cylinder, a piston-rod fixed to the smaller piston, a retractin g-sprin g bearing on said smaller piston, a tubular projection on the larger piston which enters a recess in the smaller piston and initially bears thereon, a spring-seated valve controlling the passage offluid through the larger piston to the space between the two pistons and a by-pass or conduit controlled by a cock or valve and leading from the space between the two pistons to the supply side of the larger piston.

9. ln a brake apparatus, the combination, substantially as set forth, of a pump adapted to he intermittently operated from a car-axle, a brake-cylinder having a piston connected to a brake-shoe, a pipe system through which liquid may be circulated by the pump, a valve controlling the traverse of liquid in the pipe system, a pivoted lever and connections for transferring the pump into and out of position for operation, a dog or latch for holding said lever in adjusted position, and a pivoted hand-lever having connections for moving the transferring-lever and releasing the dog or latch, and for closing and releasing the controlling-Valve Without changing the position of the transferring-lever.

In testimony whereof I have hereunto set my hand. Y

FRANCIS L. CLARK. lVitnesses J. SNOWDEN BELL, F. E. GAITHER. 

